1. Field of the Invention
This invention relates to an optical coupler for splitting an optical signal.
2. Description of the Related Art
Used as an optical coupler for splitting an optical signal incident from one optical fiber and emitting to a plurality of optical fibers is an optical coupler in which a sheet-like light guide and an optical fiber are joined.
If such an optical coupler and optical fiber are joined using a connector, the joint of the optical coupler and optical fiber weakens and the signal loss increases, and the structure of the connection part of the optical coupler and optical fiber becomes complicated.
In such a case, it is also difficult to increase the number of outputs of the optical coupler.